Deprecate cirq_google.ConvertToXmonGates and replace with cirq.CZTargetGateset + cirq.optimize_for_target_gateset

cirq-core/cirq/transformers/target_gatesets/compilation_target_gateset.py

@@ -183,7 +183,8 @@ def _decompose_single_qubit_operation(
     ) -> DecomposeResult:
         """Decomposes (connected component of) 1-qubit operations using gates from this gateset.
 
-        By default, rewrites every operation using a single `cirq.PhasedXZGate`.
+        By default, rewrites every operation `op` using a single `cirq.PhasedXZGate` if `op`
+        is not contained in self or if `op` is a newly merged connected component of operations.
 
         Args:
             op: A single-qubit operation (can be a tagged `cirq.CircuitOperation` wrapping
@@ -197,6 +198,7 @@ def _decompose_single_qubit_operation(
         return (
             ops.PhasedXZGate.from_matrix(protocols.unitary(op)).on(op.qubits[0])
             if protocols.has_unitary(op)
+            and (op not in self or self._intermediate_result_tag in op.tags)
             else NotImplemented
         )
 

cirq-core/cirq/transformers/target_gatesets/cz_gateset.py

@@ -38,7 +38,11 @@ def __init__(self, *, atol: float = 1e-8, allow_partial_czs: bool = False) -> No
         super().__init__(
             ops.CZPowGate if allow_partial_czs else ops.CZ,
             ops.MeasurementGate,
-            ops.AnyUnitaryGateFamily(1),
+            ops.XPowGate,
+            ops.YPowGate,
+            ops.ZPowGate,
+            ops.PhasedXPowGate,
+            ops.PhasedXZGate,
             name='CZPowTargetGateset' if allow_partial_czs else 'CZTargetGateset',
         )
         self.atol = atol

cirq-google/cirq_google/devices/xmon_device.py

@@ -16,7 +16,6 @@
 
 import cirq
 from cirq import _compat
-from cirq_google.optimizers import convert_to_xmon_gates
 
 if TYPE_CHECKING:
     import cirq
@@ -52,6 +51,7 @@ def __init__(
                 cirq.XPowGate,
                 cirq.YPowGate,
                 cirq.PhasedXPowGate,
+                cirq.PhasedXZGate,
                 cirq.MeasurementGate,
                 cirq.ZPowGate,
             ),
@@ -72,10 +72,15 @@ def qubit_set(self) -> FrozenSet[cirq.GridQubit]:
 
     @_compat.deprecated(
         deadline='v0.15',
-        fix='XmonDevice.decompose_operation is deperecated. Please use ConvertToXmonGates().',
+        fix='XmonDevice.decompose_operation is deprecated. '
+        'Please use cirq.optimize_for_target_gateset() and cirq.CZTargetGateset.',
     )
     def decompose_operation(self, operation: cirq.Operation) -> cirq.OP_TREE:
-        return convert_to_xmon_gates.ConvertToXmonGates().convert(operation)
+        return [
+            *cirq.optimize_for_target_gateset(
+                cirq.Circuit(operation), gateset=cirq.CZTargetGateset(allow_partial_czs=True)
+            ).all_operations()
+        ]
 
     def neighbors_of(self, qubit: cirq.GridQubit):
         """Returns the qubits that the given qubit can interact with."""
@@ -109,6 +114,7 @@ def is_supported_gate(cls, gate: cirq.Gate):
                 cirq.XPowGate,
                 cirq.YPowGate,
                 cirq.PhasedXPowGate,
+                cirq.PhasedXZGate,
                 cirq.MeasurementGate,
                 cirq.ZPowGate,
             ),
@@ -154,6 +160,7 @@ def _check_if_exp11_operation_interacts(
                 cirq.XPowGate,
                 cirq.YPowGate,
                 cirq.PhasedXPowGate,
+                cirq.PhasedXZGate,
                 cirq.MeasurementGate,
                 cirq.ZPowGate,
             ),

cirq-google/cirq_google/devices/xmon_device_test.py

@@ -52,6 +52,7 @@ def test_device_metadata():
         cirq.XPowGate,
         cirq.YPowGate,
         cirq.PhasedXPowGate,
+        cirq.PhasedXZGate,
         cirq.MeasurementGate,
         cirq.ZPowGate,
     )

cirq-google/cirq_google/optimizers/convert_to_xmon_gates.py

@@ -16,6 +16,10 @@
 import cirq
 
 
+@cirq._compat.deprecated_class(
+    deadline='v1.0',
+    fix='Use cirq.optimize_for_target_gateset and cirq.CZTargetGateset instead.',
+)
 class ConvertToXmonGates(cirq.PointOptimizer):
     """Attempts to convert strange gates into XmonGates.
 

cirq-google/cirq_google/optimizers/convert_to_xmon_gates_test.py

@@ -40,8 +40,10 @@ class NonNativeGate(cirq.SingleQubitGate):
 def test_avoids_infinite_cycle_when_matrix_available():
     q = cirq.GridQubit(0, 0)
     c = cirq.Circuit(OtherX().on(q), OtherOtherX().on(q))
-    cirq_google.ConvertToXmonGates().optimize_circuit(c)
+    with cirq.testing.assert_deprecated("Use cirq.optimize_for_target_gateset", deadline='v1.0'):
+        cirq_google.ConvertToXmonGates().optimize_circuit(c)
     cirq.testing.assert_has_diagram(c, '(0, 0): ───PhX(1)───PhX(1)───')
+
     cirq.protocols.decompose(c)
 
 
@@ -52,7 +54,10 @@ def test_avoids_infinite_cycle_when_matrix_available():
 def test_bad_operation():
     c = cirq.Circuit(NonNativeGate().on(q[0]))
     with pytest.raises(TypeError):
-        cirq_google.ConvertToXmonGates().optimize_circuit(c)
+        with cirq.testing.assert_deprecated(
+            "Use cirq.optimize_for_target_gateset", deadline='v1.0'
+        ):
+            cirq_google.ConvertToXmonGates().optimize_circuit(c)
 
 
 @pytest.mark.parametrize(
@@ -68,4 +73,5 @@ def test_bad_operation():
 )
 def test_supported_operation(op, is_valid):
     c = cirq.Circuit(op)
-    assert (cirq_google.ConvertToXmonGates().optimization_at(c, 0, op) is not None) == is_valid
+    with cirq.testing.assert_deprecated("Use cirq.optimize_for_target_gateset", deadline='v1.0'):
+        assert (cirq_google.ConvertToXmonGates().optimization_at(c, 0, op) is not None) == is_valid

cirq-google/cirq_google/optimizers/optimize_for_sycamore.py

@@ -20,7 +20,6 @@
 import cirq
 from cirq_google import ops as cg_ops
 from cirq_google.optimizers import (
-    convert_to_xmon_gates,
     ConvertToSycamoreGates,
     ConvertToSqrtIswapGates,
 )
@@ -29,29 +28,6 @@
     import cirq_google
 
 
-def _get_xmon_optimizers(
-    tolerance: float, tabulation: Optional[cirq.TwoQubitGateTabulation]
-) -> List[Callable[[cirq.Circuit], None]]:
-    if tabulation is not None:
-        # coverage: ignore
-        raise ValueError("Gate tabulation not supported for xmon")
-
-    return [
-        convert_to_xmon_gates.ConvertToXmonGates().optimize_circuit,
-    ]
-
-
-def _get_xmon_optimizers_part_cz(
-    tolerance: float, tabulation: Optional[cirq.TwoQubitGateTabulation]
-) -> List[Callable[[cirq.Circuit], None]]:
-    if tabulation is not None:
-        # coverage: ignore
-        raise ValueError("Gate tabulation not supported for xmon")
-    return [
-        convert_to_xmon_gates.ConvertToXmonGates().optimize_circuit,
-    ]
-
-
 def _get_sycamore_optimizers(
     tolerance: float, tabulation: Optional[cirq.TwoQubitGateTabulation]
 ) -> List[Callable[[cirq.Circuit], None]]:
@@ -68,12 +44,15 @@ def _get_sqrt_iswap_optimizers(
 
 
 _OPTIMIZER_TYPES = {
-    'xmon': _get_xmon_optimizers,
-    'xmon_partial_cz': _get_xmon_optimizers_part_cz,
     'sqrt_iswap': _get_sqrt_iswap_optimizers,
     'sycamore': _get_sycamore_optimizers,
 }
 
+_TARGET_GATESETS = {
+    'xmon': lambda atol, _: cirq.CZTargetGateset(atol=atol),
+    'xmon_partial_cz': lambda atol, _: cirq.CZTargetGateset(atol=atol, allow_partial_czs=True),
+}
+
 
 @lru_cache()
 def _gate_product_tabulation_cached(
@@ -131,7 +110,7 @@ def optimized_for_sycamore(
         ValueError: If the `optimizer_type` is not a supported type.
     """
     copy = circuit.copy()
-    if optimizer_type not in _OPTIMIZER_TYPES:
+    if optimizer_type not in _OPTIMIZER_TYPES and optimizer_type not in _TARGET_GATESETS:
         raise ValueError(
             f'{optimizer_type} is not an allowed type.  Allowed '
             f'types are: {_OPTIMIZER_TYPES.keys()}'
@@ -141,16 +120,16 @@ def optimized_for_sycamore(
     if tabulation_resolution is not None:
         tabulation = _gate_product_tabulation_cached(optimizer_type, tabulation_resolution)
 
-    opts = _OPTIMIZER_TYPES[optimizer_type](tolerance=tolerance, tabulation=tabulation)
-    for optimizer in opts:
-        optimizer(copy)
-    if optimizer_type.startswith('xmon'):
+    if optimizer_type in _TARGET_GATESETS:
         copy = cirq.optimize_for_target_gateset(
             circuit,
-            gateset=cirq.CZTargetGateset(
-                atol=tolerance, allow_partial_czs=optimizer_type.endswith('partial_cz')
-            ),
+            gateset=_TARGET_GATESETS[optimizer_type](tolerance, tabulation),
         )
+    if optimizer_type in _OPTIMIZER_TYPES:
+        opts = _OPTIMIZER_TYPES[optimizer_type](tolerance=tolerance, tabulation=tabulation)
+        for optimizer in opts:
+            optimizer(copy)
+
     copy = cirq.merge_single_qubit_gates_to_phxz(copy, atol=tolerance)
     copy = cirq.eject_phased_paulis(copy, atol=tolerance)
     copy = cirq.eject_z(copy, atol=tolerance)